This invention generally relates to waste water treatment and more particularly to a system for filtering solids from waste water and removing water from the solids.
In the conventional waste water treatment process one of the final steps involves the separation of solids from the water and the drying or "dewatering" of the removed solids (or sludge). Typically, this process includes the steps of chemically treating the waste water with a polymer known as a "flocking agent" to promote the aggregation of suspended solid particles. Next the treated waste water is fed into a tank or pond where the solids are permitted to settle. Finally, the water is drawn off, the solids are removed by mechanical means and dried.
Dewatering systems of this type are relatively slow and inefficient. The settling process requires about 24 hours at a minimum, thus limiting the amount of waste water that can be processed in any particular tank or pond. The systems include numerous moving parts and electric motors, so the operational and maintenance expenses are relatively high. For example, the direct operating cost of a system designed to process twenty thousand gallons per day is approximately $8.00 to $15.00 per thousand gallons of waste water processed.
Accordingly, it is an object of this invention to provide for a gravity dewatering system which will separate solids from waste water more rapidly than presently known systems.
It is the further object of this invention to provide for a gravity dewatering system which requires substantially less energy to operate than current systems.
Finally, it is yet another object of this invention to provide for a gravity dewatering system for waste water which involves fewer moving parts and thus has a lower operating cost than current systems.